Retort agitation system and method

ABSTRACT

A system for agitating products in a retort includes a clamping assembly configured to selectively impose a first clamping force on a first end of at least one product carrier and a second opposing clamping force on a second end of the at least one product carrier, and a reciprocating assembly configured to apply linear forces on the product carriers for reciprocal movement of the product carriers along the retort.A method of processing products in a retort includes arranging products in at least one product carrier for movement along a retort and reciprocating the at least one product carrier along the retort in a non-sinusoidal pattern of movement.

FIELD OF THE INVENTION

The present invention relates to retort systems for in-containerpreservation of food products, and more particularly to a system andmethod for processing food products in a retort wherein the foodproducts are agitated during thermal processing.

BACKGROUND

Retorts have been widely used for in-container preservation of foodproducts for commercial pasteurization or sterilization processes. Aretort generally includes a pressure vessel for receiving containerscontaining food products (hereinafter sometimes referred to as“in-container food products”, “products”, “containers”, “foodstuffs”, orthe like) arranged in baskets or on trays that are stacked on pallets orother types of carrier structures. The commercialsterilization/pasteurization of the food products can occur by applyingheating media to the in-container food products, including, for example,super-heated steam or hot water. Such heating media can be applied byspraying onto the stacked containers. Alternatively, the heating mediacan be introduced into the retort vessel to immerse the containersholding the food products.

Rather than utilizing a static system wherein the containers are heldstationary within the retort vessel during pasteurization orsterilization, an agitating retort can be employed. Agitation of thefood products during pasteurization/sterilization in a retort can resultin a shorter processing time and improved quality and presentation(e.g., color) of the food product. Semi-convective products and thosecontaining particulates especially benefit from agitation. Theimprovement in the presentation of the food product stems in part from alower thermal load or burden having to be applied to the food product toaccomplish the required level of pasteurization or sterilization.

The agitation of in-container food products in a retort has beenaccomplished by different systems. In one system the pallets/carriers ofcontainers are loaded within a drum positioned within the retort vessel.The drum is rotated about its longitudinal axis to produce end-over-endagitation of the food product. Although end-over-end agitation is quiteeffective, it does require a drive system to rotate the drum as well asan extensive support structure for the drum during rotation within theretort, as well as systems for introducing the processing fluid into therotating drum. Moreover, each in-container food product does notnecessarily have the same G-force/motion profile. For example, thecontainers at the center of the basket will experience different motionthan the products at the edges of the basket.

Another type of agitation retort relies on linear agitation of thein-container food product. By moving the food product back-and-forthover a relatively short distance within the retort, the change indirection at the end points of the back and forth travel results indeceleration and acceleration forces in the containers that induce anagitation effect on its content. The effect of linear agitation is lessthan that achievable by end-over-end agitation; however, in many casessuch “light agitation” can sufficiently reduce the processing timeand/or avoid clumping of the food product, to be warranted relative tosimply static thermal processing of the food product. Moreover, linearagitation allows for a simpler design than end-over-end agitation.

A typical linear agitation system includes the drive mechanismconsisting of a crankshaft rotated by a motor. Both the crankshaft andmotor are located outside one end of the retort. A connecting rod systemconnects a crankshaft to the retort pallet/carrier. Relatively heavyduty drive systems are required in these types of linear agitationsystems, including the need to counterbalance and smooth out the forcesapplied to the in-container food product by the rotating crankshaft.This counterbalancing is typically accomplished through the use of oneor more flywheels. Although a crankshaft/flywheel system is simple andreliable, it has its limitations.

For instance, crankshaft/flywheel systems are limited to sinusoidalmovement of the containers. In other words, the containers are limitedto back and forth sinusoidal motion in the retort because the motion iscoming from a rotating disc. As such, the G-force of the agitatingbaskets is directly limited by the stroke length (crank length) and thecycles/minute (rotary crank speed) of the agitation. In that regard, theagitation pattern is restricted to the same stroke length and movementpattern, regardless of the type of food product being agitated and/orthe phase of sterilization/pasteurization.

A commercial sterilization/pasteurization process for a retort systemmay include three phases. During a first come-up phase, the retortvessel goes from a starting temperature, such as room temperature, to asecond cook temperature for thermal processing the food products. Asecond cook/hold phase of the process involves holding the temperatureof the vessel at the cook temperature. Finally, during a third coolingphase of the process, the vessel is cooled back down to normaltemperatures.

During each phase of the process, the food product may change inconsistency, texture, etc. For instance, certain food products canbecome soft as they are cooked. As such, it may be desirable to use aless aggressive agitation pattern during some or all of the cook/holdphase of the process to prevent deterioration of the food product. Inanother example, the food product may release starch as it is heated,resulting in a thickening of the food product. For such a product, itmay be desirable to use a more aggressive agitation pattern during alater portion of the heating and/or cooling phases to help ensure a moreeven thermal processing of the food product.

Thus, it can be appreciated that a retort agitation system capable ofbeing varied in stroke length, speed, acceleration, and G-force tocreate a custom agitation pattern for a specific food product wouldresult in optimal thermal processing.

SUMMARY

A system for agitating products in a retort includes a clamping assemblyconfigured to selectively impose a first clamping force on a first endof at least one product carrier and a second opposing clamping force ona second end of the at least one product carrier, and a reciprocatingassembly configured to apply linear forces on the product carriers forreciprocal movement of the product carriers along the retort.

A retort system includes a processing vessel configured to receive atleast one product carrier, a low friction support system for supportingthe at least one product carrier for movement along the processingvessel, a clamping assembly configured to selectively impose a firstclamping force on a first end of the at least one product carrier and asecond opposing clamping force on a second end of the at least oneproduct carrier, and a reciprocating assembly configured to apply linearforces on the at least one product carrier for reciprocal movement ofthe at least one product carrier along the processing vessel.

A method of processing products in a retort includes arranging productsin at least one product carrier for movement along the retort, imposinga first clamping force on a first end of the at least one productcarrier and a second opposing clamping force on a second end of the atleast one product carrier, and applying reciprocating forces to the atleast one product carrier.

A method of processing products in a retort includes arranging productsin at least one product carrier for movement along a retort andreciprocating the at least one product carrier along the retort in anon-sinusoidal pattern of movement.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to identify key features ofthe claimed subject matter, nor is it intended to be used as an aid indetermining the scope of the claimed subject matter.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated by reference to thefollowing detailed description, when taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is an isometric view of a retort having a retort agitation systemformed in accordance with an exemplary embodiment of the presentdisclosure;

FIG. 2A is an isometric cross-sectional view of the retort having aretort agitation system shown in FIG. 1 , wherein the retort agitationsystem is shown in a first, loading/unloading position;

FIG. 2B is a side view of the retort having a retort agitation systemshown in FIG. 2A;

FIG. 2C is an isometric view of a first clamping subassembly of theretort having a retort agitation system shown in FIG. 2A;

FIG. 2D is an isometric view of a second clamping subassembly of theretort having a retort agitation system shown in FIG. 2A;

FIG. 3A is an isometric cross-sectional view of the retort having aretort agitation system shown in FIG. 1 , wherein the retort agitationsystem is shown in a second, loaded position;

FIG. 3B is a side view of the retort having a retort agitation systemshown in FIG. 3A;

FIG. 3C is an isometric view of a first clamping subassembly of theretort having a retort agitation system shown in FIG. 3A;

FIG. 3D is an isometric view of a second clamping subassembly of theretort having a retort agitation system shown in FIG. 3A;

FIG. 4A is an isometric cross-sectional view of the retort having aretort agitation system shown in FIG. 1 , wherein the retort agitationsystem is shown in a third, clamped position;

FIG. 4B is a side view of the retort having a retort agitation systemshown in FIG. 4A;

FIG. 5 is an exemplary embodiment of a carrier for use in the retorthaving a retort agitation system shown in FIGS. 1-4 ;

FIG. 6 is an exemplary method for agitating a load within a retorthaving a having a retort agitation system shown in FIGS. 1-4 ;

FIG. 7 is a graph showing a first exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 8 is a graph showing a second exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 9 is a graph showing a third exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 10 is a graph showing a fourth exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 11 is a graph showing a fifth exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 12 is a graph showing a sixth exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 13 is a graph showing a seventh exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 14 is a graph showing an eighth exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort;

FIG. 15 is a graph showing an ninth exemplary non-sinusoidal agitationpattern for thermal processing a load within a retort

FIG. 16A is a graph showing a prior art position, velocity, andacceleration profile for a sinusoidal agitation pattern for thermalprocessing a load within a retort at a first rotation crank speed;

FIG. 16B is a graph showing a prior art position, velocity, andacceleration profile for a sinusoidal agitation pattern for thermalprocessing a load within a retort at a second rotation crank speed;

FIG. 16C is a graph showing a prior art position, velocity, andacceleration profile for a sinusoidal agitation pattern for thermalprocessing a load within a retort at a third rotation crank speed; and

FIG. 17 is a graph showing a position, velocity, and accelerationprofile for a non-sinusoidal agitation pattern for thermal processing aload within a retort

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings, where like numerals reference like elements, is intended as adescription of various embodiments of the disclosed subject matter andis not intended to represent the only embodiments. Each embodimentdescribed in this disclosure is provided merely as an example orillustration and should not be construed as preferred or advantageousover other embodiments. The illustrative examples provided herein arenot intended to be exhaustive or to limit the disclosure to the preciseforms disclosed. Similarly, any steps described herein may beinterchangeable with other steps, or combinations of steps, in order toachieve the same or substantially similar result.

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of exemplary embodiments ofthe present disclosure. It will be apparent to one skilled in the art,however, that many embodiments of the present disclosure may bepracticed without some or all of the specific details. In someinstances, well-known process steps have not been described in detail inorder not to unnecessarily obscure various aspects of the presentdisclosure. Further, it will be appreciated that embodiments of thepresent disclosure may employ any combination of features describedherein.

The present application may include references to “directions,” such as“forward,” “rearward,” “front,” “back,” “distal,” “proximal” “upward,”“downward,” “in,” “out,” “extended,” “advanced,” and “retracted.” Thesereferences and other similar or corresponding references in the presentapplication are only to assist in helping describe and understand thepresent disclosure and are not intended to limit the present disclosureto these directions.

The present application may also reference quantities and numbers.Unless specifically stated, such quantities and numbers are not to beconsidered restrictive, but exemplary of the possible quantities ornumbers associated with the present application. Also in this regard,the present application may use the term “plurality” to reference aquantity or number. In this regard, the term “plurality” is meant to beany number that is more than one, for example, two, three, four, five,etc. The term “about,” “approximately,” etc., means plus or minus 5% ofthe stated value.

The following description and illustrations provided herein are directedto a retort agitation system and method for in-container commercialsterilization of food products that is capable of being varied in atleast stroke length, speed, acceleration, and G-force to create a customagitation pattern for the food product. Although the retort agitationsystem and method is described as being useful for food productscontained in pouches, the retort agitation system and method may also beuseful for preserved foods in other types of containers, such ascartons, cans, bottles, tubs, trays, etc. Accordingly, the descriptionsand illustrations provided herein should not be seen as limiting.

The retort agitation system and method will now be described in detail.In particular, a system for agitating in-container food products duringa commercial sterilization/pasteurization process will first bedescribed.

FIGS. 1-4 illustrates an exemplary embodiment of a retort agitationsystem 20 for use with a thermal processing vessel 24 having a vesselbody 28 enclosed by a dished head 32 at a back end and a vessel door(not shown for clarity) at a front end. It will be appreciated thatFIGS. 1-4 do not show all the details of a typical retort, such as thedetailed aspects of the system for introducing the heating medium intothe retort or for removing and/or recirculating the heating medium.These aspects of retort vessels are known to those familiar with retortdesign and technology. Different heating media and delivery systems canbe utilized, including spraying superheated water onto the productcontainers or filling the interior of the retort with hot water orsaturated steam, for example.

The vessel 24 is configured to receive a load defined by one or moreproduct carriers, such as front and rear baskets 36 a and 36 b(hereinafter sometimes generally called “baskets 36”) configured to holdin-container food products (not shown) in a manner well known in theart. In one exemplary embodiment, the baskets 36 are configured to holda plurality of pouches containing a food product (not shown). In anotherembodiment, as shown in FIG. 5 , the product carriers are defined by oneor more trays 236 stacked on a pallet (not shown) in a manner well knownin the art. When using a tray 236, the in-container food products areloaded (either manually or automatically) into pockets 240 of the tray236 for thermal processing. The load may instead be defined by any othersuitable product carrier(s) configured for holding a plurality ofin-container food products, such as pouches, cans, bottles, tubs, trays,etc.

The baskets 36 are loadable onto a low friction support system in thevessel 24 either manually or with a loading device such as a shuttle, achain conveyor drive, etc. The low friction support system is configuredto support the baskets 36 as they are loaded into the vessel 24 and asthey are agitated for low friction movement along the interior of thevessel. This can be accomplished by different means. In the depictedembodiment, the low friction support system is defined by two or moreroller assemblies 40 extending along a length of the vessel 24 in abottom section of the vessel 24 (only one roller assembly shown in thecross-sectional views). The roller assemblies 40 bear against theunderside of the baskets 36 in a known manner. For instance, the rollerassemblies 40 may be defined by rollers aligned in a track that arereceivable within correspondingly shaped grooves 38 defined on a bottombase portion 44 a and 44 b, respectively, of the front and rear baskets36 a and 36 b (sometimes referred to as the “base portion 44 of thebaskets 36” or the like).

In an alternative embodiment, rollers can be axled to the underside ofbaskets 36. In such an embodiment, appropriate bearings can beinterposed between the rollers and their axles to minimize therotational friction on the rollers. As yet another alternative, balls inthe form of ball bearings can be used in place of rollers. The ballbearings can be mounted in the floor structure of the vessel 24 or tothe base portion 44 of the baskets 36. It should be appreciated that thelow friction support system may instead be defined with any othersuitable structure suitable.

With the baskets 36 loaded onto the roller assemblies 40 in the vessel24, the baskets may be reciprocated linearly (hereinafter sometimesdescribed as “agitated” or the like) along the length of the vessel 24by the retort agitation system 20. The retort agitation system 20 isgenerally configured to agitate the baskets 36 in a non-sinusoidaland/or customizable pattern optionally through direct coupling of theagitation system to the baskets 36. In that regard, the retort agitationsystem 20 generally includes a reciprocating assembly 48 configured toagitate the baskets 36 with variable input to create a non-sinusoidaland/or customizable pattern, and a clamping assembly 50 configured todirectly secure the baskets 36 to the reciprocating assembly foragitation.

The reciprocating assembly 48 will first be described in detail. Thereciprocating assembly 48 is configured to linearly move the baskets 36back and forth along a length of the vessel 24 with variable input suchthat the agitation is not limited to a sinusoidal pattern of movement.In the depicted embodiment, the reciprocating assembly 48 includes avariable input drive mechanism 54 suitable for driving a reciprocatingmember or rod 58 back and forth along a length of the vessel 24.

One or more rod supports 60 may extend from a bottom portion of thevessel 24 for supporting the reciprocating rod 58 as it is moved backand forth in the vessel 24. The rod support(s) 60 may be any suitablelow friction device configured to maintain the axial alignment of thereciprocating rod 58 with the drive mechanism 54 while allowing thereciprocating rod 58 to move back and forth without substantialrestriction. For instance, the rod support(s) 60 may be defined by abushing secured to a bracket or other mounting assembly. Any othersuitable support assembly may instead be used.

A suitable anti-rotation feature(s) may be used to substantially preventthe reciprocating rod 58 from rotating about its longitudinal axis. Forinstance, a keyed slot may be defined along a length of thereciprocating rod 58 that receives a key extending from a suitablestructure that interfaces with the reciprocating rod 58. In that regard,the rod support(s) 60 may include a key configured to interface with akeyed slot on the reciprocating rod 58, or the anti-rotation feature mayinstead be defined on other components as described below.

The variable input drive mechanism 54 is capable of moving the rod 58 ina forward and backward direction by reversing the drive direction, asopposed to a prior art flywheel system that only rotates in onedirection. The drive mechanism 54 may be any variable input drivemechanism suitable for driving the reciprocating rod 58 linearly backand forth along a length of the vessel 24 in a customized(non-sinusoidal) agitating pattern. In the depicted embodiment, thedrive mechanism 54 is a hydraulic linear actuator having a cylinder 55with a piston rod 56 coupled to and in axial alignment with thereciprocating rod 58. The piston rod 56 may be coupled at its distal endto the rear end of the reciprocating rod 58 in any suitable manner, suchas with a coupling assembly 57. It should be appreciated that otherdrive mechanisms may instead be used, such as an electric linearactuator, a servo motor, first and second pneumatically controlled airbags configured to engage the front and rear baskets 36 a and 36 b,respectively, a pneumatic/hydraulic piston, or any other mechanicalactuator that is configured to impart a linear force through a linearstroke.

The drive mechanism 54 includes suitable electrical and/or mechanicalcomponents configured to independently vary the stroke length of thereciprocating rod 58, pause/stop the reciprocating rod 58 between strokeactuations/motions, vary the G-force of the reciprocating rod 58, etc.,to create a customized non-sinusoidal agitating pattern. For instance,if the drive mechanism 54 is configured as a hydraulic cylinder, it mayinclude suitable valves and controls for driving the rod 58 in aspecific pattern and/or with a specific acceleration, speed, etc. Inthis manner, the reciprocating rod 58 (and therefore the baskets 36) canbe moved in a variety of different agitating patterns specific to theagitation needs of the food product in the containers. For instance, thedrive mechanism 54 is configured to move the reciprocating rod 58 in atleast the agitating patterns shown and described with respect to FIGS.7-15 .

In one aspect, the drive mechanism 54 may include a position sensor orfeedback device for monitoring the linear position of the piston rod 56(and therefore the reciprocating rod 58) during the thermal process. Forinstance, a linear encoder may be used to sense the linear position ofthe piston rod 56 and to output one or more signals indicative of therod position to an integrated or separate (wired or wireless) controller(not shown). The controller may be configured to, in response to the oneor more encoder signals, output one or more signals to the drivemechanism 54 for activating and controlling the speed, acceleration,direction, etc., of the reciprocating rod 58 (such as by controlling aproportional valve of the hydraulic cylinder to follow a pre-programedagitation motion profile). The controller may be any suitable electronicclient device, such as a computer, personal digital assistant, cellphone, tablet computer, or any other suitable device in which computersoftware or other digital content may be executed. The electronic clientdevice can be controlled either directly or by a remote connection usingindustry standard communication protocols such as HART, Modbus, 4-20 mA,and H1, as well as other protocols.

The drive mechanism 54 may be mounted to a support structure 64 that isexternal to the vessel 24. In this manner, the drive mechanism 54 neednot be configured to withstand the internal extreme temperaturevariations of the vessel 24. Moreover, by being located outside thevessel 24 on a separate structure, the vessel 24 will not be susceptibleto the main reciprocating forces of the drive mechanism 54. In thatregard, the support structure 64 is any suitable structure configured tolocate the reciprocating rod 58 along a desired reciprocating axis forengaging and agitating the baskets 36 and for withstanding the mainreciprocating forces of the drive mechanism 54. However, it should beappreciated that the drive mechanism 54 and support structure 64 mayinstead be configured to be located inside the vessel 24.

With the drive mechanism 54 located outside the vessel 24, however, thereciprocating rod 58 can pass through the dished head 32 of the vessel24 via a suitable rod sealing/bushing member 59 having a central bore(not labeled). A suitable sealing interface (such as with an O-ring,etc.) may be defined between an exterior surface of the rodsealing/bushing member 59 and the dished head 32 of the vessel 24 andbetween an interior surface of the rod sealing/bushing member 59 and thereciprocating rod 58.

The clamping assembly 50 configured to directly secure the baskets 36 tothe reciprocating assembly 48 for agitation will now be described indetail. The clamping assembly 50 includes a first clamping subassembly62 defined at a front end of the reciprocating rod 58 and a secondclamping subassembly 66 defined at a back end of the reciprocating rod58 for engaging and imposing opposing clamping forces on the front andrear baskets 36 a and 36 b, respectively. In that regard, the first andsecond clamping subassemblies 62 and 66 also secure the baskets 36 a and36 b together.

Referring to FIGS. 2A-2C, 3A-3C, and 4A-4B, the first clampingsubassembly 62 is generally configured to selectively engage and imposea clamping force on the front basket 36 a. More specifically, the firstclamping subassembly 62 is moveable between a first position, where thefirst clamping subassembly 62 is disengaged from the front basket 36 aand the baskets 36 are free to be loaded/unloaded from the retort (seeFIGS. 2A-2C), and a second position, where the first clampingsubassembly 62 is positioned to engage and impose a clamping force onthe front basket 36 a (see FIGS. 3A-3C and 4A-4B). The first clampingsubassembly 62 is moveable between the first and second positions byextending and retracting the reciprocating rod 58, respectively. Thefirst clamping subassembly 62 may be any suitable configuration forselecting engaging and imposing a clamping force on the front basket 36a.

In the depicted embodiment, the first clamping subassembly 62 isgenerally configured as a tailgate mechanism configured to selectivelyengage and impose a clamping force on the front basket 36 a. Morespecifically, the first clamping subassembly 62 includes a pivot arm 72pivotally secured to a front end of the reciprocating rod 58 through abracket 74 or other suitable structure. A first pivot pin 78 extendstransversely through a first end of the pivot arm 72 and through thebracket 74 to define a first pivot axis that is transverse to thelongitudinal axis of the reciprocating rod 58. The pivot arm 72 ismoveable along and pivotal about a pivot roller 82 secured in a bottomof the vessel 24. As the reciprocating rod is extended and retractedtoward the front and back of the vessel 24, the pivot arm 72 rolls alongand pivots about the pivot roller 82 between a lowered and raised orfirst and second position.

More specifically, the pivot arm 72 is moveable about the first pivotaxis between at least the first position, where the pivot arm 72 ispivoted downwardly and out of axial alignment with the reciprocating rod58 (see FIGS. 2A-2C), and the second position, where the pivot arm 72 isin axial alignment with the reciprocating rod 58 (see FIGS. 3A-3C and4A-4B). The pivot arm 72 is moveable into the first position by movingthe reciprocating rod 58 forward with the drive mechanism 54 until thepivot axis of the first pivot pin 78 is substantially aligned with thepivot axis of the pivot arm roller 82. With this substantial alignment,the pivot arm roller 82 is no longer providing support beneath the pivotarm 72 so the pivot arm 72 can pivot downwardly about the pivot axis ofthe first pivot pin 78.

The pivot arm 72 is moveable into the second position by retracting thereciprocating rod 58 with the drive mechanism 54. As the reciprocatingrod 58 is retracted, the outer surface of the roller 82 urges the pivotarm 72 upwardly until it is aligned with the axis of the reciprocatingrod 58. A first carrier or basket stop 84 extends transversely from thefront end of the pivot arm 72 and is positioned to engage the frontbasket 36 a when the pivot arm 72 is moved upwardly into the secondposition. In the depicted embodiment, the basket stop 84 is positionedto engage a clamp engagement plate 68 defined on a bottom base portion44 a on the front end of the front basket 36 a.

The clamp engagement plate 68 extends downwardly from the bottom baseportion 44 a of the front basket 36 a such that the first basket stop 84can be moved in front of the clamp engagement plate 68 as it is movedinto the second position. In this second position, the reciprocating rod58 may be retracted toward the back of the vessel 24 until the firstbasket stop 84 imposes a clamping force on the front of the clampengagement plate 68. The anti-rotation feature(s) described hereinensure alignment of the first basket stop 84 with the clamp engagementplate 68 as it is moved into the second position.

An opposing clamping force is imposed on the rear basket 36 b by thesecond clamping subassembly 66 after the reciprocating rod 58 is movedinto the retracted position. The second clamping subassembly 66 may beany suitable configuration that is generally configured to selectivelyengage and impose a clamping force on the rear basket 36 b with thereciprocating rod 58 in the retracted position.

In the depicted embodiment, the second clamping subassembly 66 includesa second carrier or basket stop 90 that is moveable along thereciprocating rod 58 between a first position, where the second basketstop 90 is disengaged from the rear basket 36 b (see FIGS. 3A, 3B, and3D), and a second position, where the second basket stop 90 is engagedwith and imposes a clamping force on the rear basket 36 b (see FIGS.4A-4B). The second basket stop 90 is a suitable configuration to bemoveably coupled to the reciprocating rod 58 and to be engaged with therear basket 36 b. For instance, the second basket stop 90 may besubstantially cylindrically shaped having a central bore 92 forreceiving the reciprocating rod 58.

The second basket stop 90 is defined on a distal end of a clamping rod94 configured to be moved toward and away from the rear basket 36 b. Theclamping rod 94 can be moved linearly toward the rear basket 36 b untilthe second basket stop 90 imposes a clamping force on the bottom portion44 b of the rear basket 36 b, and it can be moved linearly away from therear basket 36 b to release the clamping force. In the depictedembodiment, the clamping rod 94 is concentrically located on thereciprocating rod 58 such that it moves along the same axis as thereciprocating rod 58 (and in this regard, the clamping rod 94 isessentially a tube). In that regard, the clamping rod 94 includes acentral bore 96 for receiving the reciprocating rod 58, and bushings 100and 101 or another low friction interface, such as bearings,lubrication, etc., (are disposed between the clamping rod 94 and thereciprocating rod 58 such that the clamping rod 94 may slide easilyalong the reciprocating rod 58. The clamping rod 94 also extends along alength of the reciprocating rod 58 such that it extends into and out ofthe vessel 24 through the rod sealing/bushing member 59. In that regard,a bushing 103 or other suitable low-friction interface may also bedisposed between the rod sealing/bushing member 59 the clamping rod 94to allow the clamping rod 94 (and reciprocating rod 58) to easily slidetherethrough.

Referring to FIG. 2D, the rod sealing/bushing member 59 may also includean anti-rotation feature to substantially prevent rotation of theclamping rod 94 about its longitudinal axis. For instance, a first keyedslot 63 may be defined along a length of the clamping rod 94 thatreceives a key 65 extending transversely through the rod sealing/bushingmember 59. Moreover, the second basket stop 90 may include ananti-rotation feature to prevent the reciprocating rod 58 from rotatingabout its longitudinal axis, such as a key 93 extending transverselythrough the cylindrical body of the second basket stop 90 that isreceivable within a slot 95 extending along a length of thereciprocating rod 58.

The clamping rod 94 is moveable toward and away from the rear basket 36b through any suitable drive mechanism. For instance, the clamping rod94 may be moved by a hydraulic linear actuator 98 having a piston rod102 extending from a cylinder 104. However, it should be appreciatedthat other mechanisms may instead be used, such as an electric linearactuator, a servo motor, a pneumatic/hydraulic piston, or any othermechanical actuator that is configured to impart a force to move rod 94in a linear direction along the length of rod 58.

In one aspect, the hydraulic linear actuator 98 may include a positionsensor or feedback device for monitoring the linear position of thepiston rod 102 (and therefore the clamping rod 94) during the thermalprocess. For instance, a linear encoder may be used to sense the linearposition of the piston rod 102 and to output one or more signalsindicative of the rod position to an integrated or separate (wired orwireless) controller (not shown). The controller may be configured to,in response to the one or more encoder signals, output one or moresignals to the hydraulic linear actuator 98 for activating andcontrolling the movement of the clamping rod 94.

The hydraulic linear actuator 98 is arranged such that the piston rod102 moves the clamping rod 94 linearly toward and away from the rearbasket 36 b as the piston rod 102 is extended and retracted,respectively, from the cylinder 104. This may be carried out in anysuitable manner. For instance, in the depicted embodiment, the hydrauliclinear actuator 98 extends between a first rod attachment member 108secured to the clamping rod 94 and a second rod attachment member 110secured to the reciprocating rod 58. As the piston rod 102 is extended,the first rod attachment member 108 and the clamping rod 94 collectivelymove away from the second rod attachment member 110 and toward the rearbasket 36 b. At the same time, the second rod attachment member 110remains in a fixed position on the reciprocating rod 58. The piston rod102 may be extended until the second basket stop 90 defined at the endof the clamping rod 94 engages and imposes a clamping force on the rearbasket 36 b.

In a clamping position, as shown in FIGS. 4A-4B, the first and secondbasket stops 84 and 90 impart opposing clamping forces on the front andrear baskets 36 a and 36 b to secure the baskets together and to securethe baskets to the reciprocating rod 58 for agitation. Suitable spacers130, such as bumpers, gaskets, etc., may be disposed between the frontand rear baskets 36 a and 36 b to provide sufficient bearing area forthe clamping force exerted on the baskets when they are being agitated,and/or to allow thermal processing fluid to pass between the baskets 36a and 36 b for optimal thermal processing.

Referring to FIG. 6 , an exemplary method for directly securing (ordetaching) the baskets 36 to (or from) the reciprocating assembly 48 foragitation will now be described. The method of securing the baskets 36may start after the clamping assembly 50 is in a first, clamped positionat step 308, wherein the first and second clamping subassemblies 62 and66 cooperatively impose a linear clamping force on the baskets 36, asshown in FIGS. 4A-4B. This may be at the end of a thermal process of aload (e.g., commercial sterilization of food products contained inbaskets or trays). Instead, the clamping assembly 50 may be in thefirst, clamped position with no baskets 36 yet loaded into the vessel24.

Regardless, with the clamping assembly 50 in a first, clamped position,the method includes initial steps for moving the clamping assembly 50into a second, unclamped position such that carriers, such as baskets 36may be unloaded from or loaded into the vessel 24. To move the clampingassembly 50 into the second, unclamped position, at step 310 the secondbasket stop 90 is retracted with the corresponding retraction of thepiston rod 102 of the hydraulic linear actuator 98 to release theclamping force exerted by the clamping assembly 50 on the baskets 36.

Referring to FIGS. 3A-3C, the second basket stop 90 is shown retractedrearwardly on the reciprocating rod 58 and disengaged from the rearbasket 36 b. The stroke length of the piston rod 102 may be predefinedto ensure that there will be sufficient clearance to extend thereciprocating rod 58 and allow the first clamping subassembly 62 todisengage the front basket 36 a. In other words, there is sufficientclearance between the axial position of the rear basket 36 b and theretracted second basket stop 90 such that the second basket stop 90 cantravel forward with the reciprocating rod 58 without engaging the rearbasket 36 b in the next step 314.

In that regard, when the second basket stop 90 is retracted, thereciprocating rod 58 can be extended, or moved forward within the vessel24 by the drive mechanism 54, as indicated in step 314. As thereciprocating rod 58 is extended, the first clamping subassembly 62disengages the front basket 36 a, as shown in FIGS. 2A-2C. Morespecifically, the pivot arm 72 moves along a roller plane defined by thepivot roller 82 toward the front of the vessel 24 until the first pivotpin 78 is substantially aligned with the pivot roller 82. Such alignmentmay occur with the reciprocating rod 58 extended to a firstpredetermined stroke length of the drive mechanism 54. At this point,the pivot arm 72 can rotate downwardly about the axis of the first pivotpin 78. As the pivot arm 72 rotates downwardly, the first carrier orbasket stop 84 disengages from and moves out of the forward moving pathof the front basket 36 a, as indicated by step 318 and as shown in FIGS.2A-2C. A sensor(s) of the drive mechanism 54 can be used to track thelinear position of the piston rod 56 (and thus the reciprocating rod 58)to indicate when it has been extended the predetermined first strokelength; and therefore, when the pivot arm 72 has pivoted downwardly.

Once the reciprocating rod 58 extends the first predetermined strokelength and the first basket stop 84 disengages from and moves out of theforward moving path of the front basket 36 a, as indicated by steps 314and 318, the baskets 36 can be unloaded from and/or loaded into thevessel 24, as indicated by step 322. When the baskets 36 are loaded intothe vessel 24, the baskets 36 are loaded onto the roller assemblies 40and moved toward the rear of the vessel 24 until the rear basket 36 bengages the second basket stop 90. The clamping assembly 50 may then bemoved back into the first, clamped position such that the baskets may beagitated during thermal processing.

To move the clamping assembly 50 back into the first, clamped position,the reciprocating rod 58 is retracted at step 326 to correspondinglymove the pivot arm 72 rearwardly. The pivot arm 72 moves along a rollerplane defined by the pivot roller 82 toward the rear of the vessel 24while pivoting upwardly about the axis of the first pivot pin 78. Thereciprocating rod 58 is retracted a second predetermined stroke lengthof the drive mechanism 54 until the first basket stop 84 engages theclamp engagement plate 68 of the front basket 36 a, as indicated in step330 and as shown in FIGS. 3A-3C. A sensor(s) of the drive mechanism 54can be used to track the linear position of the piston rod 56 (and thusthe reciprocating rod 58) to indicate when it has been retracted thesecond predetermined stroke length to rotate the pivot arm 72 upwardly.

As the reciprocating rod 58 is retracted at step 326, the entire secondclamping subassembly 66 retracts as well. Thus, once the reciprocatingrod 58 is retracted to engage the first basket stop 84 with the clampengagement plate 68 of the front basket 36 a, as indicated in step 330,the drive mechanism of the second clamping subassembly 66 is activatedin step 334 to move the second basket stop 90 forward along thereciprocating rod 58. The second basket stop 90 is moved forward alongthe reciprocating rod 58 from the first position, where the secondbasket stop 90 is disengaged from the rear basket 36 b (see FIGS. 3A-3Band 3D), into the second position, where the second basket stop 90 isengaged with and imposes a clamping force on the rear basket 36 b (seeFIGS. 4A-4B).

More specifically, the clamping rod 94 is moved forwardly when thepiston rod 102 of the hydraulic linear actuator 98 extends from thecylinder 104 a third predetermined stroke length. The piston rod 102extends the third predetermined stroke length (detectable by sensor(s))so that the second basket stop 90 is engaged with and imposes a clampingforce on the rear basket 36 b. Since the pivot arm 72 is already in theup position, the first and second clamping subassemblies 62 and 66cooperatively impose a linear clamping force on the baskets 36 to securethe baskets 36 a and 36 b together and to secure the baskets to thereciprocating rod 58. In other words, the front and rear baskets 36 aand 36 are clamped between the first and second basket stops 84 and 90.In this manner, the reciprocating forces of the drive mechanism 54 caneffectively be transferred to the baskets 36 for agitation.

In that regard, at step 338, the reciprocating rod 58 is reciprocated bythe drive mechanism 54 to agitate the baskets 36. The baskets 36 areagitated in a customized (optionally non-sinusoidal) pattern until thethermal process has completed, as indicated in step 342. Once thethermal process has completed, the method steps may be repeated tounload the baskets 36 from the vessel 24 and load a new set of carriers(baskets, trays, etc.) into the vessel 24 for thermal processing.

The retort agitation system 20 of the present disclosure includes areciprocating assembly 48 that is capable of varying the stroke length,speed (stroke position/time) frequency (cycles/minute), acceleration,and G-force of the load to create a custom (optionally non-sinusoidal)agitation pattern or motion profile for the specific food product. Forinstance, the stroke length can be adjusted (lengthened or shortened)during the thermal process to accommodate a viscosity change in the foodproduct. As a specific example, as a food product heats up, theviscosity of the product may decrease, and a longer stroke length mightbetter match the natural “sloshing” motion of the food product.

The agitation speed and/or frequency can also be changed during theagitation motion profile of a food product. For example, it may bebeneficial to adjust the agitation speed and/or frequency when the foodproduct has a fluid inside the container that heats quickly, but it alsohas particles that heat at a slower rate. Such a food product maybenefit from a higher agitation speed and/or frequency at the beginningof the thermal process to help the fluid in the container heat quickly,and a slower speed and/or frequency once the fluid is heated and theparticles continue to heat. If a slower agitation speed and/or frequencycan be used, the agitation equipment would endure less wear and tear,and energy is saved.

The agitation motion profile may also be designed to allow for the loadto be agitated at different acceleration and G-forces during the thermalprocess. For instance, certain food products that become fragile, softor delicate during the thermal process can have an agitation motionprofile with a high acceleration/G-force at the beginning of the thermalprocess (such as during some or all of come-up), and then once the foodproduct starts to soften the agitation motion profile can be changed tohave a lower (gentler) acceleration/G-force to avoid damaging the foodproduct.

The agitation motion profile with the customized stroke length, speed,frequency, acceleration, and/or G-forces can be applied as a constantvariable over a specific time period or phase of the thermal process.For example, an aggressive agitation profile can be used during aninitial heating of product, a less aggressive agitation profile can beused when the food product is hot because it can become more fragile,and then finally a more aggressive agitation profile can be used oncethe product has cooled or has become thicker due to starches beingreleased during the cooking process. The agitation motion profile withthe customized stroke length, speed, frequency, acceleration, and/orG-forces can also be applied as a variable function that, for instance,increases and decreases over multiple strokes and then repeats in apattern during at least one of the initial product heating phase(come-up), the cook phase, and the cool phase.

FIGS. 8-15 depict non-limiting examples of non-sinusoidal agitationpatterns for thermal processing a food product within a retort. Thenon-sinusoidal agitation patterns graphically depicted in FIGS. 8-15 maybe carried out with a reciprocating assembly similar to reciprocatingassembly 48 described above, or with any other suitable reciprocatingassembly.

The exemplary agitation motion profile graphically depicted in FIG. 8includes more intense accelerations resulting from a higher speed in thecome-up and end of cool phases, and gentler accelerations from a lowerspeed during the cook phase and a first part of the cool phase. In thisexemplary agitation motion profile the stroke length and frequencyremains substantially constant. Such an agitation motion profile may bebeneficial for a food product that becomes fragile when heated, asdiscussed above. In an alternative embodiment, the cook phase and firstpart of the cool phase may include more intense accelerations (higherspeed) for a less fragile product, whereas gentler accelerations may beused during the come-up and end of cool phases. The accelerations mayinstead be varied during some or all of the phases as needed toefficiently process the food product.

The exemplary agitation motion profile graphically depicted in FIG. 9 isan “agitate and pause” repeated profile, which may be used during someor all of the thermal processing phases, and for the total phase or aportion of the phase. More specifically, the load may be agitated backand forth along the retort several times, paused, and then agitatedagain in a repeated or varied pattern. A “pause” is understood to be astop in the movement of the load that is more than an interruption ofmovement that occurs when the load reverses directions (i.e., when theload technically comes to a stop before changing directions). Forinstance, a “pause” may include a stop in movement that is greater than,for instance, 0.1 seconds.

Such an “agitate and pause” profile could be used to periodicallyaggressively agitate or shake the food product to mix its contents (forimproved heat transfer), but to pause the aggressive agitation/mixing tohelp maintain the integrity of the food product. It can be appreciatedthat a constant aggressive agitation/mixing of the food (i.e., it isshaken constantly during the process) might cause the food product todeteriorate. The agitation motion profile graphically depicted in FIG. 9could include one “hard shake” and a pause, several hard shakes and apause, or any other combination or pattern suitable for the foodproduct. The stroke length, speed, frequency, acceleration, and G-forceremain substantially constant during the agitation portion of theagitation motion profile graphically depicted in FIG. 9 ; however itshould be appreciated that one or more of those could instead be varied.

The exemplary agitation motion profile graphically depicted in FIG. 10is a “variable stroke length” agitation motion profile, which may beused during some or all of the thermal processing phases, and for thetotal phase or a portion of the phase. More specifically, the load maybe agitated back and forth along the retort while varying the strokelength and speed for each cycle (where one cycle equals one completeforward motion and one complete reverse motion to return the load to thehome position) but while keeping the frequency (cycles/minute) constant,resulting in larger or smaller accelerations. More specifically, bykeeping the frequency substantially constant, the agitation motionprofile would include larger accelerations (G-force) imposed on the foodproduct for a longer stroke length per unit of time, and smalleraccelerations (G-force) for a shorter stroke length per unit of time.Such an agitation motion profile can be achieved as graphically depictedin FIG. 10 , where the profile has a substantially constant frequency(i.e., t1, t2, and t3 being substantially equal) but each cycle includesa different stroke length from the previous cycle (such as one of threedifferent stroke lengths). The pattern could be repeated as shown. Forinstance, the variable stroke length agitation motion profile couldinclude four strokes at 0.5″, four strokes at 1″, six strokes at 0.6″,with each stroke occurring within about the same time duration, and thenrepeat. Such a patterned variable stroke length agitation motion profileresulting in different accelerations imposed on the food product couldbe beneficial for a food product that has different viscosities as thefood product heats and cools.

The exemplary agitation motion profile graphically depicted in FIG. 11is a “fast acceleration in one direction” profile, which may be usedduring some or all of the thermal processing phases, and for the totalphase or a portion of the phase. More specifically, the load may beagitated back and forth along the retort with a generally fastacceleration in a first direction (i.e., when extending thereciprocating rod 58), and a slow acceleration a (i.e., when retractingreciprocating rod 58) in the return direction. In the exemplaryagitation motion profile graphically depicted in FIG. 11 , the speed andfrequency remain substantially constant, although they could instead bevaried. Such a “fast acceleration in one direction” agitation motionprofile could be beneficial for containers like pouches, tubs or otherfood containers that typically slide back and forth on or in a carrierduring agitation.

For instance, if the carrier is a tray, such as the tray 236 shown inFIG. 5 , the in-container food products are loaded into pockets 240 ofthe tray 236 for thermal processing. A sufficient tolerance is typicallydefined between the edges of the pockets 240 and the food productcontainer to accommodate automatic or robotic loading of the containerinto the pocket. This “slop” allows the in-container food product tomove back and forth within the pocket 240 during agitation, scuffing orabrading certain containers (such as pouches) during the process,especially when heated. Accordingly, the agitation motion profile can becustomized to help maintain the position of the container against anedge of the pocket such that any abrasion or scuffing of the containeris avoided or minimized.

More specifically, by quickly accelerating the food container in thefirst direction with a slow deceleration at the end of the stroke, andreturning in the opposite direction with a slow acceleration and a fastdeceleration at the end of the stoke, the food container would getpushed up against one side or edge of the retort tray pocket and stay atthat edge for the duration of the thermal process (or for a certainportion of the thermal process, as desired). In other words, theagitation force is substantially applied in only one direction. In thismanner, a clamping mechanism or the like is not needed to keep thecontainer in a secured position against an edge of the tray pocket. Itshould be appreciated that this agitation motion profile may also beused to secure any suitable container (such as cans or bottles) withinany suitable carrier (such as a basket).

The agitation motion profile of a food product may also be varied byimposing pauses, stops, or impulses on the load during one or morephases of thermal processing. For instance, the load may be moved in onedirection at a high speed, paused or stopped, then moved in the samedirection at a slower speed to impose varied G-forces on the foodproduct. The magnitude, stroke length, and frequency of the impulse maybe varied to create a desired agitation effect on the food product massinside the container.

The exemplary agitation motion profile graphically depicted in FIG. 12is a “fast acceleration in one direction” profile that is substantiallysimilar to the profile depicted in FIG. 11 , which may be used duringsome or all of the thermal processing phases, and for the total phase ora portion of the phase. In the agitation motion profile graphicallydepicted in FIG. 12 , however, the agitation is paused or stoppedbetween the fast acceleration in the first direction (i.e., by extendingthe reciprocating rod 58) and a slow acceleration to return in thesecond direction (by retracting the reciprocating rod 58). For instance,the load may be moved fast in a first direction, stopped hard, returnedat a slower speed, stopped slowly, and then repeated with the same speedand/or frequency or with a different speed and/or frequency as shown.With such an agitation profile, the agitation force is substantiallyapplied in only one direction such that the food container will staypositioned up against an edge of the tray or basket.

The exemplary agitation motion profile graphically depicted in FIG. 13is also a “fast acceleration in one direction” profile that issubstantially similar to the profile depicted in FIG. 12 and that may beused during some or all of the thermal processing phases, and for thetotal phase or a portion of the phase. In the agitation motion profilegraphically depicted in FIG. 13 , however, the agitation is paused orstopped as it is being moved in the first direction (by extending thereciprocating rod 58) at a fast acceleration before being returned inthe second direction (by retracting the reciprocating rod 58) at aslower acceleration. For instance, the load may be moved fast in a firstdirection, stopped hard, moved fast again in the first direction,stopped hard, moved fast again in the first direction, stopped hard, andthen returned at a slower speed and stopped slowly. This pattern may berepeated during some or all of the phases (or a portion of thephase(s)). With such an agitation profile, the agitation force is againsubstantially applied in only one direction such that the food containerwill stay positioned up against an edge of the tray or basket. Differentmotion profiles can be created to accelerate and stop the load multipletimes in a “forward” direction, before changing direction and returningthe load to a “home” position in a single movement or with multiple stopand starts.

The exemplary agitation motion profile graphically depicted in FIG. 14is a “multiple strokes in one direction” profile that is substantiallysimilar to the profile depicted in FIG. 13 in that the load is moved andstopped/paused several times in a first direction (by extending thereciprocating rod 58). However, in the agitation motion profilegraphically depicted in FIG. 14 , the load is also moved andstopped/paused several times in a second return direction (by retractingthe reciprocating rod 58) at a similar speed and stroke length. Theagitation motion profile graphically depicted in FIG. 14 may be usedduring some or all of the thermal processing phases, and for the totalphase or a portion of the phase.

The exemplary agitation motion profile graphically depicted in FIG. 15is a “combination” agitation motion profile, which may be used duringsome or all of the thermal processing phases, and for the total phase ora portion of the phase. More specifically, the load may be agitated backand forth along the retort while varying the stroke length, the speed,frequency, acceleration, and/or the G-forces in a repeatable orsemi-repeatable pattern. The agitation motion profile of FIG. 15 is arepresentation of a combination of some or all of the agitation motionprofiles discussed above. For instance, the load may be first be movedfast in a first direction, stopped hard, moved less fast in the firstdirection, stopped hard, moved faster in in the first direction, stoppedhard, etc., and then returned at a slower speed to the home position.Once reaching the home position, the load may be agitated back and forthat the same stroke length, speed, and frequency, and then paused.Finally, the load may be agitated at several repeated strokes of thesame stroke length, speed, and frequency at a starting point between thehome and return positions. This pattern may be repeated during some orall of the phases (or a portion of the phase(s)).

It can be appreciated that the agitation effects of the above-describedagitation motion profiles may be achieved with any non-sinusoidalmotion, such as a saw tooth profile, an s-curve profile, a trapezoidalprofile, etc. Moreover, it should be appreciated that theabove-described exemplary agitation motion profiles may be modified orcombined as needed to most efficiently and effectively thermally processthe specific food product in the containers. Moreover, although themotion profiles are graphically shown in terms of stroke position andtime, it can be appreciated that the acceleration and g-force acted uponthe food product, which are derivatives of the position and velocityagitation motion profiles as will be described below with respect toFIGS. 16 and 17 , are significant factors for imposing the necessaryagitation of a food product within the container.

Some or all of the above-described agitation motion profiles may becarried out with certain preferred ranges of stroke length, speed,frequency, and G-force or acceleration, which, either alone or incombination, result in effective agitation. For instance, the strokelength may stay within a broad range of between about one-tenth of aninch (0.10″) to about ten inches (10″), or within a narrower subset ofthat broader range, such as about one-eighth inch (⅛″) to about teninches (10″), about one-tenth of an inch (0.10″) to about two inches(2.0″), about a half an inch (0.5″) to about one and one quarter inches(1.25″) or two inches (2″), or any other range suitable for the intendedfood product or profile.

The above-listed exemplary stroke length ranges are defined as thedistance that the load moves between a start and stop position. As canbe appreciated from the above-described exemplary agitation motionprofiles, the profile can include several starts and stops in a singledirection before returning to the “home position.” (See FIGS. 13-15 .)As an example, using an agitation motion profile similar to the onegraphically depicted in FIG. 13 , the load may be moved from the homeposition forward one inch (1″), stopped, moved forward one and a halfinches (1.5″), stopped, moved forward one inch (1″), stopped, movedforward one and a half inches (1.5″), stopped, and then returned fiveinches (5″) to the home position. In that regard, the total cycle lengthbetween the home and return position may be the sum of the individualstroke lengths.

The frequency, or cycles per minute for the above-described agitationmotion profiles may be carried out within a range of between about 5-200cycles/minute, and more preferably about 10-200 cycles/minute, and morepreferably about 20-100 cycles/minute. As noted above, one cycle isequal to one complete forward motion and one complete reverse motion toreturn the load to the home position. It should be appreciated that thefrequency may be dependent upon the type of agitation motion profileused, and it may be varied throughout the cycle. The G-force for theabove-described agitation motion profiles may be within a range ofbetween about 0.05 G-2 G, or more preferably about 0.3 G-1 G.

The agitation motion profiles may be stored in memory in a computer inthe form of a recipe computer program module (“recipe module”) for thespecific food product. The computer may be in wired or wirelesscommunication with the controller of the retort agitation system 20, orthe computer may instead be a part of the controller. The memory maystore computer-readable, computer executable software/firmware codethat, when executed, cause the controller to perform various functionsas described herein, such as actuating the variable input drivemechanism 54 to execute a specific agitation motion profile. Forinstance, the controller may be may be configured to output one or moresignals to the drive mechanism 54 for activating and controlling thestroke position, speed, acceleration, length, direction, time to pausebetween strokes, etc., of the reciprocating rod 58 in response to theexecution of one or more recipe modules.

The controller will also be in wired or wireless communication with oneor more feedback devices, such as a sensor(s), that will monitor thestatus, position, etc., of the retort agitation system components 20 toensure the contained food product is experiencing the correct agitationmotion profile, and/or to adjust the profile as needed. For instance,the agitation motion profile may be automatically adjusted for thingssuch as inconsistent frictional forces and ordinary part wear. Ofcourse, there will be limits to the corrections that can be made with anautomated system, in which case the retort agitation system 20 mayinclude alarms or other feedback devices that can alert operators whenmaintenance is needed.

As can be appreciated from the foregoing, the retort agitation system 20configured to agitate a load in a non-sinusoidal and/or customizablepattern optionally through direct coupling of the agitation system tothe load provides several benefits over prior art systems. For instance,prior art systems that use a traditional crank shaft have the G-forcevariable tied to the rotary crank speed (RPM) and crank length. Astandard agitation motion profile for thermal processing a load inside aretort using a traditional crank shaft is sinusoidal, meaning the strokelength remains constant for each cycle (where one cycle equals onecomplete forward motion and one complete reverse motion to return theload to the home position). Accordingly, the G-force can be increased ordecreased only by adjusting the rotational speed (and therefore thestrokes/minute) of the crankshaft.

To help illustrate this point, FIGS. 16A-16C graphically depictexemplary first, second, and third position, velocity, and accelerationcurves for a prior art crank shaft and flywheel system having a standardsinusoidal agitation motion, wherein the stroke length for each curve issubstantially the same (about 6 inches). The first curve shown in FIG.16A represents a position, velocity, and acceleration curve at a rotarycrank speed of 30 RPMs, the second curve shown in FIG. 16B represents aposition, velocity, and acceleration curve at a rotary crank speed of 40RPMs, and the third curve shown in FIG. 16C represents a position,velocity, and acceleration curve at a rotary crank speed of 120 RPMs. Ascan be appreciated by a comparison of these curves, an acceleration ofabout 0.09 G's can be achieved at 30 RPMS (about 9.36 inches/second oflinear movement), an acceleration of about 0.14 G's can be achieved at40 RPMS (about 12.17 inches/second of linear movement), and anacceleration of about 1.37 G's can be achieved at 120 RPMS (about 37.45inches/second of linear movement). To achieve a suitably highacceleration or G-force for agitation, a significantly high rotary crankspeed (RPM) must be used. Moreover, the rotary crank speed would need tobe increased at a significantly higher rate if a shorter stroke lengthwas used.

By comparison, FIG. 17 graphically depicts an exemplary position,velocity, and acceleration curve for a non-sinusoidal agitation motionprofile formed in accordance with embodiments of the present disclosure.An acceleration of about 0.25 G's can be achieved using only a strokelength of 1.0 inches. Moreover, by using a variable input drivemechanism 54, the stroke length and speed can be independently varied toimpart a desired acceleration/G-force on the specific food product. Forinstance, the retort agitation system 20 can impart a varied strokelength during a thermal sterilization process, and it can increase theG-force output per stroke and decrease the strokes per minuteexperienced by the load. Prior art systems using crank shafts, on theother hand, have to increase the speed (cycles per minute) to increasethe G-force imposed on the load.

Thus, by using a retort agitation system having a variable input drivemechanism, such as the retort agitation system 20 having the drivemechanism 54 described above, the motion profile of the food products inthe carriers can be attuned to the changing properties of the foodproducts while minimizing wear and tear on the reciprocating assembly48. Moreover, the thermal processing time of the food products may bereduced while maintaining the same commercial sterility levels, the foodproduct quality may be improved even with reduced thermal processingtimes, and the integrity of delicate/fragile food products can bemaintained by varying the motion profile at certain times during thethermal process, among other benefits.

For instance, non-sinusoidal, customizable agitation motion profiles canreduce the thermal processing time by about 40-50% for some foodproducts while maintaining the same sterilization Fo value. Of note, thein-container food product is held at a cook temperature until aspecified Fo value is met, where the Fo value is a unit of lethality,i.e., how quickly a population of bacteria is destroyed. The faster thefood product is heated, the faster the Fo value will accrue.Accordingly, if the food product is heated up faster during the initialheating phase, it is held at a higher temperature for an overall shorteramount of time to achieve the same Fo value for food safety. Thus, itcan be appreciated that with a shorter initial heating phase of the foodproduct (achievable with a non-sinusoidal, customizable agitation motionprofile as described herein), the total time that the productexperiences high thermal processing temperatures decreases, (initialheating phase+hold phase of food product). As a result, the quality ofthe contained food product increases.

The inventors performed preliminary testing to measure the improvedthermal processing efficiencies using a retort agitation system inaccordance with the present disclosure. The retort agitation system wasconfigured to impose non-sinusoidal agitation motion profiles using aconstant speed and stroke length throughout the entire thermal processwith an imposed G-force of between about 0.75 G-0.9 Gs. The followingresults were achieved for a paper board carton containing eitherminestrone soup or chicken soup with about a 9 mm headpace in thecontainer, and with an Fo value of 6.

Cook Time (Minutes) Processing Mode Minestrone Soup Chicken Noodle SoupStatic 27.6 20.8 Non-Sinsoidal Agitation 15.7 9.4

As can be appreciated, a retort using a non-sinusoidal agitation motionprofile reduces the thermal processing time of both food products byabout 45%-50% in comparison to a static retort.

The following results were achieved for a gallon pouch having athickness of one and a half inches (1.5″) and containing either pintobeans or mushrooms, with an Fo value of 7, and where the come-up phasewas 16 minutes.

Cook Time (Minutes) Processing Mode Pinto Beans Mushrooms Static 31.622.8 Rocking 23.7 12.43 Non-Sinsoidal Agitation 19.1 10.8

As can be appreciated, a retort using a non-sinusoidal agitation motionprofile reduces the thermal processing time of both food products byabout 30%-50% in comparison to a static retort and by about 25%-45% incomparison to a retort using a rocking motion profile.

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A system for agitatingproducts in a longitudinal retort, comprising: a reciprocating assembly,comprising: a reciprocating drive member with a reciprocating drive axisin substantially coaxial alignment with a longitudinal axis of theretort, the reciprocating drive member moveable linearly along thelongitudinal axis of the retort such that it is configured to applylinear forces on at least one product carrier for a reciprocalnon-sinusoidal pattern of movement of the at least one product carrieralong a length of the retort; and a variable input first drive mechanismconfigured to move the reciprocating drive member linearly back andforth along the reciprocating drive axis by alternating between firstand second drive directions of the variable input first drive mechanism;a clamping assembly defined on the reciprocating drive member,comprising: a first clamping subassembly having a first carrier stopconfigured to selectively impose a first clamping force on a first endof the at least one product carrier; and a second clamping subassemblyhaving a second carrier stop including a bore, wherein the reciprocatingdrive member passes through the bore such that the second carrier stopis slidable axially on the reciprocating drive member by a second drivemechanism and configured to selectively impose a second opposingclamping force on a second end of the at least one product carrier. 2.The system of claim 1, wherein the second carrier stop is moveableaxially along the reciprocating drive member between a first position,where the second carrier stop is disengaged from the second end of theat least one product carrier, and a second position, where the secondcarrier stop is engaged with the second end of the at least one productcarrier for linear movement with the reciprocating drive member.
 3. Thesystem of claim 1, wherein the first clamping subassembly is configuredas a tailgate mechanism with the first carrier stop configured toselectively engage the first end of the at least one product carrierwhen the reciprocating drive member is moved in a first direction anddisengage the first end of the at least one product carrier when thereciprocating drive member is moved in a second direction, wherein thefirst clamping subassembly includes a pivot arm pivotally secured to afirst end portion of the reciprocating drive member and the firstcarrier stop is defined on the pivot arm such that the first carrierstop is configured to engage the first end of the at least one productcarrier when the reciprocating drive member is moved in the firstdirection.
 4. The system of claim 1, wherein the variable input firstdrive mechanism is a hydraulic actuator having a position feedbackdevice configured to output one or more signals to a controllerindicative of a linear position of the reciprocating drive member, andwherein the controller is configured to process the one or more signalsfrom the position feedback device and output one or more signals to thevariable input drive mechanism for activating and controlling at leastone of a speed, acceleration, stroke length, frequency, pause timebetween strokes, and direction of the reciprocating drive member,wherein a stroke is a movement of the at least one product carrier bythe reciprocating drive member along at least a portion of the length ofthe retort.
 5. The system of claim 1, wherein, the non-sinusoidalpattern of movement is defined when the variable input first drivemechanism moves the reciprocating drive member to define a pattern ofmovement with at least one of: a plurality of strokes of the at leastone product carrier in a first direction before movement of the at leastone product carrier back in an opposite second direction, wherein astroke is a movement of the at least one product carrier by thereciprocating drive member along at least a portion of the length of theretort; and a plurality of strokes of the at least one product carrierin a first direction before movement of the at least one product carrierback in an opposite second direction with a pause in movement betweeneach of the plurality of strokes, wherein a stroke is a movement of theat least one product carrier by the reciprocating drive member along atleast a portion of the length of the retort.
 6. The system of claim 1,wherein the variable input first drive mechanism of the reciprocatingassembly is configured to vary at least one of a speed, stroke length,frequency, acceleration, pause time between strokes, direction of thereciprocating drive member, and G-force to move the at least one productcarrier along a length of the retort in a non-sinusoidal pattern ofmovement, wherein a stroke is a movement of the at least one productcarrier by the reciprocating drive member along at least a portion ofthe length of the retort.
 7. The system of claim 1, wherein an outputdrive member of the second drive mechanism is coupled to the secondcarrier stop for moving the second carrier stop between the first andsecond positions, wherein the second drive mechanism moves linearly withthe reciprocating drive member.
 8. The system of claim 1, wherein thesecond drive mechanism is one of an electric linear actuator, a servomotor, a pneumatic piston, and a hydraulic piston having a drive memberthat is moveable in response to signals received from a controller tocorrespondingly move the second carrier stop.
 9. The system of claim 1,wherein an output drive member of the second drive mechanism is coupledto the second carrier stop through a first attachment member, andwherein the second drive mechanism is coupled to the reciprocating drivemember through a second attachment member moveable with thereciprocating drive member such that the second drive mechanism moveslinearly with the reciprocating drive member.
 10. The system of claim 9,wherein a clamping rod extends between the first attachment member andthe second carrier stop, the clamping rod having a bore, wherein thereciprocating drive member passes through the bore of the clamping rodsuch that the clamping rod is slidable axially on the reciprocatingdrive member by the second drive mechanism.
 11. A system for agitatingproducts in a longitudinal retort, comprising: a reciprocating assemblycomprising: a reciprocating drive member configured to apply linearforces on at least one product carrier for a reciprocal non-sinusoidalpattern of movement of the at least one product carrier along a lengthof the retort by alternating between first and second drive directionsof a first drive mechanism; a clamping assembly configured toselectively secure at least one product carrier to the reciprocatingdrive member, the clamping assembly comprising: a first clampingsubassembly configured to secure a first end of the at least one productcarrier to a first portion of the reciprocating drive member when afirst carrier stop engages the first end of the at least one productcarrier to impose a first clamping force on the first end of the atleast one product carrier, and a second clamping subassembly configuredto secure a second end of the at least one product carrier to a secondportion of the reciprocating drive member when a second carrier stopengages the second end of the at least one product carrier to impose asecond opposing clamping force on the second end of the at least oneproduct carrier, the second carrier stop including a bore, wherein thereciprocating drive member passes through the bore such that the secondcarrier stop is slidable axially on the reciprocating drive member by asecond drive mechanism between a first position, where the secondcarrier stop is disengaged from the second end of the at least oneproduct carrier, and a second position, where the second carrier stop isengaged with the second end of the at least one product carrier forimposing the second opposing clamping force on the second end of the atleast one product carrier, wherein in the second position the secondcarrier stop moves linearly with the reciprocating drive member.
 12. Thesystem of claim 11, wherein the first clamping subassembly is configuredas a tailgate mechanism with the first carrier stop configured toselectively engage the first end of the at least one product carrierwhen the reciprocating drive member is moved in a first direction anddisengage the first end of the at least one product carrier when thereciprocating drive member is moved in a second direction, wherein thefirst clamping subassembly includes a pivot arm pivotally secured to afirst end of the reciprocating drive member, wherein the pivot armpivots into a lowered position when the reciprocating drive member ismoved in the second direction, wherein the pivot arm pivots into araised position when the reciprocating drive member is moved in thefirst direction, and wherein the first carrier stop is defined on thepivot arm such that the first carrier stop engages the first end of theat least one product carrier when the pivot arm pivots into the raisedposition.
 13. The system of claim 12, wherein the second carrier stop ismoveable into the first position such that it is disengaged from thesecond end of the at least one product carrier when the first carrierstop is being moved between the engaged and disengaged positions, andwherein the second carrier stop is moveable into the second positionsuch that it is engaged with the second end of the at least one productcarrier when the first carrier stop is in the engaged position.
 14. Asystem for agitating products in a longitudinal retort, comprising: areciprocating assembly, comprising: a reciprocating drive memberconfigured to apply linear forces on at least one product carrier for areciprocal non-sinusoidal pattern of movement of the at least oneproduct carrier along a length of the retort; a variable input firstdrive mechanism configured to move the reciprocating drive memberlinearly back and forth along a length of the retort by alternating adrive direction of the variable input first drive mechanism; acontroller that is configured to send at least one signal to thevariable input first drive mechanism to define the non-sinusoidalpattern of movement by at least one of: a plurality of strokes of the atleast one product carrier in a first direction before movement of the atleast one product carrier back in an opposite second direction, whereina stroke is a movement of the at least one product carrier by thereciprocating drive member along at least a portion of the length of theretort; a plurality of strokes of the at least one product carrier in afirst direction before movement of the at least one product carrier backin an opposite second direction with a pause in movement between each ofthe plurality of strokes, wherein a stroke is a movement of the at leastone product carrier by the reciprocating drive member along at least aportion of the length of the retort; and a first acceleration of the atleast one product carrier in a first direction and a second accelerationof the at least one product carrier lower than the first acceleration ina second opposite direction; and a clamping assembly defined on thereciprocating drive member, the clamping assembly comprising: a firstclamping subassembly having a first carrier stop configured toselectively impose a first clamping force on a first end of the at leastone product carrier; and a second clamping subassembly having a secondcarrier stop including a bore, wherein the reciprocating drive memberpasses through the bore such that the second carrier stop is slidableaxially on the reciprocating drive member by a second drive mechanismand configured to selectively impose a second opposing clamping force ona second end of the at least one product carrier.
 15. A system foragitating food products in a longitudinal retort configured to support athermal process of a food product through at least a first phase and asecond phase, wherein the first phase creates a first food producttemperature different than a second food product temperature of thesecond phase, and wherein the food product has a first foodcharacteristic during the first phase of the thermal process and asecond food characteristic during the second phase of the thermalprocess, the system for agitating food products in a longitudinal retortcomprising: a reciprocating assembly, comprising: a reciprocating drivemember configured to apply linear forces on at least one product carrierfor a reciprocal non-sinusoidal pattern of movement of the at least oneproduct carrier along a longitudinal axis of the retort; a variableinput first drive mechanism configured to move the reciprocating drivemember linearly back and forth along the longitudinal axis of the retortby alternating a drive direction of the variable input first drivemechanism; and; a computing device for controlling the variable inputfirst drive mechanism to define the non-sinusoidal pattern of movement,the computing device having at least one processor and a non-transitorycomputer-readable medium, wherein the computing device iscommunicatively coupled to the variable input first drive mechanism,wherein the non-transitory computer-readable medium hascomputer-executable instructions stored thereon, and wherein theinstructions, in response to execution by the at least one processor,cause the variable input first drive mechanism to execute a firstagitation profile for first phase of the thermal process and a secondagitation profile for second phase of the thermal process that isdifferent in at least one of stroke length, pause duration betweenstrokes, and acceleration of strokes, wherein a stroke is a movement ofthe at least one product carrier by the reciprocating drive member alongat least a portion of the length of the retort; and a clamping assemblydefined on the reciprocating drive member, the clamping assemblycomprising: a first clamping subassembly having a first carrier stopconfigured to selectively impose a first clamping force on a first endof the at least one product carrier; and a second clamping subassemblyhaving a second carrier stop including a bore, wherein the reciprocatingdrive member passes through the bore such that the second carrier stopis slidable axially on the reciprocating drive member by a second drivemechanism and configured to selectively impose a second opposingclamping force on a second end of the at least one product carrier. 16.The system of claim 15, wherein the variable input first drive mechanismincludes a position feedback device configured to output one or moresignals to the computing device indicative of a linear position of thereciprocating assembly, and wherein the computing device is configuredto process the one or more signals from the position feedback device andoutput one or more signals to the variable input first drive mechanismfor activating and controlling at least one of a speed, acceleration,stroke length, pause duration between strokes, frequency, and directionof the reciprocating assembly.
 17. The system of claim 15, wherein thefirst agitation profile includes at least one of a saw tooth profile, ans-curve profile, and a trapezoidal profile.
 18. The system of claim 15,wherein the first agitation profile corresponds to a come-up phase ofthe thermal process and the second agitation profile corresponds to acook/hold phase of the thermal process, and wherein the first agitationprofile has first stroke acceleration higher than a second strokeacceleration of the second agitation profile.
 19. The system of claim15, wherein the first agitation profile corresponds to a come-up phaseof the thermal process and the second agitation profile corresponds to acook/hold phase of the thermal process, and wherein the first agitationprofile has first stroke length shorter than a second stroke length ofthe second agitation profile.
 20. The system of claim 15, wherein thefirst agitation profile corresponds to a come-up phase of the thermalprocess and the second agitation profile corresponds to a cook/holdphase of the thermal process, and wherein the first agitation profilehas first pause duration between strokes that is longer than a secondpause duration between strokes of the second agitation profile.